ABSTRACT
The canard configuration is a common form of layout in tactical missile, such as Russia’s “red” terminal guidance ammunition, “basij aung” gun, “gecko” air defense missiles, American paveway I, paveway II, paveway III, laser-guided bombs, France’s “magic” air-to-air missile and so on. The reason is that it has many advantages such as high efficiency rudder steering, a smaller power of steering engine, short connecting cables and easy lay. But the main disadvantage of this arrangement is that when the ailerons of missiles carry roll control, large reverse roll moment are produced on the tail because an asymmetric downwash flow field near the tail fins was induced, producing a so-called reversed rolling moment. So that the missile roll control efficiency is greatly reduced. Aiming at the problem, a lot of researches in two aspects of theory and experiment were carried to improve roll control efficiency of canard missiles. The measures of reduction induced roll torque of duck rudder are that reducing the wingspan of tail wings; using ring tail; with T blade on the tail in Figure 1; using ring tail in Figure 2; the free rotation tail.
